Spark-plug.



W H.BUCKLEY.l

SPARK PLUG. APPLICATIQN FILED SAEPT. Hi,A 1915. v

Patented Apr. 4,1916.

UMTED STATE@ WILLIAM H. BUCKLEY, OF BRIDGEPORT, CONNECTICUT.

SPARILPLUG.

Application lil-ed September 16, 1915.

To all 'rl/fiom 'it 'may conccm.'

Be it known that l, lViLLiAM H. Burattini', a citizen of the llnited States, residing at the city of Bridgeport, county of Fairlield` State of Connecticut, have invented certain new and useful Improvements in Spark-Plugs;

and l do declare the -following to be a' full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use lthe saine.

My present invention pertains to an irnprovcd spark plug for explosive engines, the construction and advantages of which will be hereinafter set forth, reference being had to the annexed drawings, wherein:

Figure l is a longitudinal sectional view of the plug, the positive or central electrode being shown in full; and Fig. 2 a bottoni plan View thereof.

Spark plugs of the same general type as that which forins the basis of this invention are old and many have been patented and also used with a greater or less degree of success. So far as l ain aware, however, such plugs are open to several objections, the main ones being that of short-circuiting, burning of the electrodes, smutting, and the deposition of carbon on the electrodes, with the consequent weakening of the spark, and diffusion of the spark, causing weakening, whereby the spark oftentimes fails to ignite the charge. A

The object of the present invention is to vproduce a structure wherein these objections and ditliculties will be overcome or obviated, and that by a construction which is at once simple and incapable of niisadjustment in assembling.

Referring to the drawings, l denotes the.

usual shell, 'the lower end 2 whereof is cylindrical and externally threaded whereby it may be screwed in place in the engine cylinder. Said shell forms the grounded electrode. The upper portion of the bore of the shell is preferably enlarged, a shoulder' il being thereby produced upon which the shouldered portion 4 of the insulating plug or bushing' finds its seat. A nut G, engaging a second shoulder 7, upon the bushing, is screwed upon the upper end of the shell, snitable'packing, as 8, being interposed uto effect a gas-tight joint, and the bushing is thus held in place.

The insulating bushing, formed of any suitrable di-electric material, is provided with a Specification of Letters Patent.

Patented A pr. 4. 1914i.

Serial No. 50,940.

longitudinal bore which is concentric with the inner cylindrical bore of the lower end 2 of the shell. and as will be noted the lower portion i) of the bore is larger in diameter than the upper portion, an inclined shoulder l0, being fol-ined at the point of niergence of the dilferent sections of the bore. i

A stein or wire 11, threaded at its upper end for the reception of suitable nuts and washers, indicated generally by 1Q; for connection of the current conductor, extends through the upper bore of the insulating bushing. The stein carries a head or enlargement 13 at its lower end, which fits against shoulder' l0, Suitable packing may be'interposed at this point, to effect a gastight joint. Head 13 is internally threaded and a second stem or wire, 14, is screwed into the saine, the stem standing away from the wall of the bushing and extending downwardly below the lower end of the saine a considerable distance, terminating in a laterally-projecting toev l5. Said toe, which is formed integrally with the stem, is flattened, and the outer end thereof is curved, the curve being somewhat sharper than that of the inner cylindrical wall of the lower end 2 of the shell l; in other word-s, the curved faces are eccentrically arranged. It will also be noted that the end of the toe or terminal is lightly curved upon its upper and lower faces, and by thus curving the same in all directions no points or angles are present at which the current would have a. tendency to localize and jump to the bushing or grounded terminal.

lith this construction there is presented a spot or space on the toe which is at the eX- act or proper sparking distance from the inner wall of the bushing, and by making the surface of the toe curved there can be no burning away, because no undue concentration or localization of the current will take place, the current merely owing around the curved surface tothe spot or space where the discharge is effected. Again, the current may be said to be gathered to the place of discharge,- and consequently there is no breaking up of the current into separate sparks or discharges, as is b ound to take place where there are any points or angles present on either terminal.

By having the stem or wire 14 extend a considerable distance 4below the insulating bushing` 5, the terminal is subjected to the `scouring action of the gas as it flows into` and @uit of the engine cylinder and. consequently ie kept clean t all times, thereby ixismfing a full discharge when i'equii'ecl. Furthermore, there are ne metallic fasten ings er peints whei-e ibhe euri-ent would have a endeney te glimp across to lie bushing, thus desti-@fing Aehe eflieieney o' the plu@ :it meiiifes that instead @if forming the pesitive eleeiede iii two sections, 1l and le, it may he produced from a single piece, but

im' obvieue lisons the two-piece construe *bien ;vielieiieil. ,it will als@ he appie- :-iee\1 ihr/e the-,e een be no mispleeemem et the me with reference to the "Wall the lo gef-ieu 2 *elle stem le; and said wall have commen axis oi' eeiiei, ieiee care. 0r line Vadjustment in assemblage is mines esszuy.

Having thug dese-filled my iiiveuien,what l claim is:

l. In a spark plug *mexplosive engine, he combination 0l :i All having a curved inner face adjacent its lower end forming ene electrode; an insulating bushing mounted in the shell; and, un electrode mounted in the bushing, extending below the same nml terminating in a single laterally-extending Shoe, that face er @nel ci ehe toe which extends toward the Wall of the shell being cm'vecl,

the eurvaauee being sharper than that of me aforesaid inner ihee of the shell, said leisen named electrode being i'ee of auf)r piojee tiens other than said toe, end lie vbody ef the eleeti'ode gradually merging into the toe.

2. 1n a, spark plug for explosive engines, ,the combination of u shell having :L eylin1 eli-ical inner surface, at its lower end, and forming one elec'ziode; un .insulating bushinga mounted in the shell; and an eleetiode 'mmmed in ehe bushing; and extending below the same, Jthe end of said electrode profa jeeting lateruily, Within the shell, in the Shape of :i ice, teiminaing adjacent the eylindrieal surface nfeiesaid, and being' free of other projections, the end or extremity e' said toeneeles's the shell being curved laterally upon e radius smaller than that. efr' the cylindrical sui-face; and likewise being slighly eur-ved upon its upper and lewer faces adjacent smid laterally Curved end, whereby :in extended curved surface is formed iee of all points 0i' projections.'

n 'testimony whereof I affix my signature in presence of two witnesses.

VLLAM H. BUCKLEY T7Vitzeesses GEORGE MCCABE, C. E. VALKER. 

